Hypertension, or elevated blood pressure is a leading risk factor for cardiovascular disease, the number one cause of death in the United States (US). Among US Hispanics, a fast growing, diverse group, anticipated to account for 29% of the US population by 2060, the epidemiology of hypertension remains inadequately described. Currently, there are notable hypertension disparities across Hispanic backgrounds, with higher rates of hypertension among US Hispanics from the Caribbean (Cubans, Dominicans, and Puerto Ricans) compared with non-Caribbean Hispanics (Mexicans, Central, and South Americans). Reasons underlying these disparities remain underexplored and unknown. The goal of this 4-year K01 project is to improve our knowledge of the epidemiology and etiology of hypertension disparities among US Hispanics, using data from a large population-based cohort of diverse US Hispanics. To do so, we determine whether key factors, that are known to vary by Hispanic background, such as: genetic admixture (as a proxy for race), acculturation, and modifiable health related factors, explain hypertension disparities across Hispanic backgrounds. This project involves analysis of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), an on-going prospective cohort of 6,160 hypertension-free US Hispanics aged 18 to 74 at the baseline examination in 2008-2011 and re-examined at follow-up in 2014-2017. The HCHS/SOL cohort includes US Hispanics of Central American, Cuban, Dominican, Mexican, Puerto Rican, and South American background residing in four communities across the US. In Aim 1, we will determine whether African admixture explains disparities in rates of hypertension between Caribbean and non-Caribbean Hispanics. In Aim 2 we will determine whether acculturation explains disparities in rates of hypertension between Caribbean and non-Caribbean Hispanics. In Aim 3, we will examine health related factors (e.g. diet, physical activity, smoking, and body mass index) as determinants of hypertension disparities and estimate the number of hypertension cases averted under simulated interventions that modify health related factors to recommended levels. The proposed analyses are embedded in a training and mentoring plan that will advance my training in: 1) genetics including admixture analysis, genetic epidemiology, and statistical genetics; 2) clinical aspects of hypertension and hypertension etiologies; 3) health disparities research; 4) complex survey methodology; and 5) casual inference techniques and simulation modeling for public health forecasting. My training plan will include formal courses, workshops, attendance at scholarly seminars and scientific conferences, directed readings and professional development activities specifically tailored to my training goals. Having the K01 support will provide the mentoring necessary to establish myself as an independent investigator and will result in preliminary data that will feed into a successful R01 application related to genetic determinants of blood pressure control among Hispanics.